This invention relates to a coupling for joining an ostomy bag to a pad or surgical dressing. Ostomy bags are usually secured to a pad or surgical dressing which contacts the user's skin and surrounds the stoma. There is a need for a coupling between pad and bag which allows the bag to be readily removed when necessary, and replaced by a clean, empty bag. At the same time, it is essential that the coupling should be a secure one, and prevent leakage particularly of liquids and gases.
Efforts have been made, see for example the proposal in British Patent Specification No. 1 021 145 published in 1966, to provide a connector whereby the bag can be readily removed and replaced. But this arrangement involves two separate operations, firstly one must unscrew the connector which carries the bag from the connector which is secured to the body and this involves a risk of leakage as it is necessary to invert the bag. Also it is an awkward operation. It will be appreciated that at this time the bag is full or partly-full of bodily waste products, and manipulation of the coupling will be an unpleasant operation even if, as is often not the case, the user has a high degree of dexterity.
British Patent Specification No. 1 009 455 discloses an appliance in which one ring co-operates with a second part-ring which is used to trap the neck of a bag when the two rings are inter-engaged with the bag mouth between them. If adequate security against leakage is to be provided, it is necessary that the two rings should be a tight fit; however, this makes it difficult for the user to pull off the part-ring and it is especially difficult for a user who is old or infirm. As the part-ring is pulled off, there is the probability that the security of attachment of the first ring to the surgical dressing, or of the dressing to the skin of the wearer will be impaired. This may also cause discomfort to the wearer.
A more recent proposal, which has enjoyed wide commercial success is described and claimed in British Pat. No. 1 571 657. The reader is also referred to British Patent Specifications Nos. 1 568 850; 1 579 875; 1 583 823 and 1 586 824. It is desirable to have a coupling for an ostomy bag which is flexible, which has the features of easy fitting and unfitting and good security of attachment and sealing, and which also has a flatter design, that is to say the coupling does not project so far outwardly from the body of the wearer, than the coupling disclosed and illustrated in Pat. No. 1 571 657.
A satisfactory ostomy bag coupling should be easy for the wearer to attach. Current designs are less than ideal in this respect. Coupling is made difficult by the desire of the designer to ensure a good seal between the two coupling elements which means that they are constructed as a tight fit one into the other, and by the fact that the wearer is attempting to apply the bag side coupling element to the body side coupling element by pushing the former forwards from the latter. However, as the stoma end and region of the stoma is tender, it is painful to the wearer if any significant portion of the considerable pushing force applied to the bag side element in coupling it to the body side element is transmitted to the body of the wearer. Only a few of the present designs of ostomy bag coupling elements known to the Applicant attempt to address this problem, and in the Applicant's belief none have solved it satisfactorily.